Construction of tunnels

ABSTRACT

Horizontally spaced tubes are located within the ground substantially horizontal with the ground surface and by working from within at least some of the tubes support means is constructed between the tubes. The tubes and support means form a structure defining the roof and at least part of the side of the tunnel under construction and after the structure has been formed the ground beneath the structure is excavated.

United States Patent m1 3,631,680

[ 72] Inventor John Crawford Thomson [56] References Cited [2]] App] NO. gsrrsaygdrg, Surrey, England UNITED STATES PATENTS [22] Filed g 24, 1969 2,074,003 3/1937 Templeton et al 61/42 X [45] Patented Jan. 4,1972 2,325,565 7/1943 wllllams 61/42 [73] Assignee Tube Headings Limmd 2,377,012 5/1945 Jacobs 61/42 croydon, Surrey, England 2,839,271 6/1958 Kandle 61/42 X [32] Prion-w June 25, 1968 3,234,743 2/1966 Levy 61/42 X 33 Great Britain FOREIGN PATENTS [31] 30,423/68 1,186,893 2/ 1965 Germany 61/42 Primary Examiner-Dennis L. Taylor 541 CONSTRUCTION or TUNNELS & Peck 2 Claims, 2 Drawing Figs. [52] US. Cl. 61/42, ABSTRACT: Horizontally spaced tubes are located within the 61/45 R ground substantially horizontal with the ground surface and by [51 1 int. Cl E0lg 3/00 working from within at least some of the tubes support means [50] Field of Search 61/42, 43, is constructed between the tubes. The tubes and support 45 R, 84, 85 means form a structure defining the roof and at least part of the side of the tunnel under construction and after the structure has been fonned the ground beneath the structure is excavated.

PATENTED JAN 41972 SHEET 1 0F 2 m ///V/////////////////V////////////////////Z w m s? 7/ V R R... m a a v R v R 4 //A\\Y/A\\7/A\\r NN I u E \VAA\\Y/A\\Y/ -'INMI; Mme

Him,

PATENTED JAN 4 I972 SHEET 2 BF 2 W eww mm W BACKGROUND OF THE INVENTION The construcu'on of a new or a replacement tunnel through the ground under a surface with the minimum disturbance of the surface.

SUMMARY A method of constructing a tunnel comprising forcing a plurality of tube sections substantially horizontally through the ground below the surface of the ground to form two or more horizontally spaced tubes extending lengthwise for a required distance, constructing from within at least one of the tubes and without disturbing the ground surface a support means extending to an adjacent tube to form a support structure, and excavating the ground beneath a major part of the support structure.

Preferably, prior to the excavation of the ground, further support means is constructed from within at least one of the tubes to extend downwardly away from the ground surface.

One or more apertures may be preformed in at least some of the tube sections to facilitate the construction of the support means. The support means may be constructed by forcing further pipe sections through the ground from within the tube sections, or by augering bores casing the bores, disposing reinforcement within the cased bores and filling them with concrete. With advantage the tube sections are jacked horizontally from a drive pit to a reception pit and are filled with concrete after the support means have been completed.

In a preferred method of construction three substantially horizontal spaced tubes are formed in the ground, the two outer tubes being located to constitute, respectively, the tops of sidewalls of the tunnel and the remaining tube being located symmetrically between and nearer the ground surface than the outer tubes, and constructing support means extending between the remaining tube and each of the outer tubes.

According to another aspect of the invention a tunnel construction comprises a plurality of tubes extending substantially horizontally through the ground below the surface thereof at longitudinally spaced intervals and support means extending between adjacent tubes.

One example of where such a construction is advantageous is in the production of a tunnel under a railway track where disturbance of the track would cause disruption of the services using the track.

DRAWINGS FIG. 1 is a vertical section through a tunnel and FIG. 2 is a section on the line H-Il of FIG. 1.

One embodiment of tunnel, constructed in accordance with the method of the invention, is now described by way of example only, reference being made to the drawings.

The tunnel is fonned below a surface (not shown) carrying or intended to carry a load, such as a railway track. As the first step, rectangular hollow precast concrete tube sections 12 having an outer dimension 1 1 feet by 1 1 feet are jacked from a drive pit on one side of the ground to be tunnelled to a reception pit on the other side. A jacking method for the tube sections in accordance with US. Pat. No. 3,234,743 issued on Feb. 15, 1966 to Gerald J. Levy may be employed in the practice of this invention. The tube sections 12 are jacked in one behind the other to form a pair of horizontally spaced tubes 13, 14 and located at positions respectively to constitute the top of a pair of walls of the tunnel being constructed. In the tunnel construction being described the tops of the tubes 13, 14 are 30 feet 9 inches below the surface of the ground being tunnelled. Each of the tube sections 12 is boxlike and is formed with a steel shuttered window 15 in the side facing the other tube. A further tube 16 is formed by jacking precast concrete boxlike tube sections 17, 6 feet 6 inches by 7 feet 6 inches in cross section substantially horizontally through the ground parallel to the tubes 13, 14 and located symmetrically between them slightly nearer ground level. The tube sections 17 have steel shuttered windows 18 on each side facing the tubes 13 and 14.

A support structure 19 to form the basis of the roof of the tunnel is then constructed by constructing support means to extend between the tubes 13 and 16 and 14 and 16. A plurality of side by side 18 inch diameter cased bores 20 are augered from within each of the tubes 13 and 14 to the tube 16 at an angle of 20 to the horizontal, by means of a Jason auger boring machine. 12 inch by 12 inch mild steel beams 21 are inserted into the bores 20 which are then filled with concrete injected from within respective tubes 13 and 14. The casings 22 of the augered bores 20 extend from the windows 15 to the windows 18 while beams 21 project beyond the casings 22 into the tubes 13, 14 and 16.

The support means for the walls of the tunnel are provided by 24 inch diameter piles 23 bored and formed from within the tubes 13 and 14 and extending vertically downwards for approximately 34 feet 3 inches below the tubes. After forming the support structure 19 and the piles 23, the pipes 13, 14 and 16 are filled with concrete, service ducts 25 being previously inserted if required. The ground under the support structure 19 is then excavated to provide a tunnel, for example for a roadway. The ceiling of the tunnel is formed by a 3 inch thick structural layer of gunite after partial excavation and the walls and floor are formed of concrete cast insitu after total excavation of the tunnel.

The support structure 19 could be formed by jacking further small tubes from within the pipes 13 and 14 to the tube 16 if desired.

In a variation the central tube 16 is omitted and the support structure constructed by jacking tubes or auger boring direct from on the tube 13 or 14 to the other.

Other arrangements of tubes extending lengthwise of the tunnel being formed could be used provided that a support structure is constructed between adjacent tubes by jacking, auger boring or the like means from within one tube to the adjacent tube without disturbing the ground surface. Instead of piles 23, a continuous concrete wall extending the tubes 14, 16 may be constructed as a support means.

I claim:

1. A method of constructing a tunnel comprising forcing a plurality of tube sections substantially horizontally through the ground below the surface of the ground to form two or more horizontally spaced tubes extending lengthwise for a required distance, in which tubes one or more apertures are preformed in at least some of the tube sections to facilitate construction of a support means; constructing from within at least one of the tubes and without disturbing the ground surface support means by forcing further tube sections through the ground from within the tube sections, which support means extends to an adjacent tube to form a support structure, constructing further support means from within at least one of the tubes to extend downwardly away from the ground surface and excavating the ground beneath a major part of the support structure.

2. A method of constructing a tunnel comprising forcing a plurality of tube sections substantially horizontally through the ground below the surface of the ground to form two or more horizontally spaced tubes extending lengthwise for a required distance, in which tubes one or more apertures are preformed in at least some of the tube sections to facilitate construction of a support means; constructing from within at least one of the tubes and without disturbing the ground surface support means by augering bores, casing the augered bores, disposing reinforcement within the cased bores and filling them with concrete, which support means extends to an adjacent tube to form a support structure; constructing further support means from within at least one of the tubes to extend downwardly away from the ground surface and excavating the ground beneath a major part of the support structure. 

1. A method of constructing a tunnel comprising forcing a plurality of tube sections substantially horizontally through the ground below the surface of the ground to form two or more horizontally spaced tubes extending lengthwise for a required distance, in which tubes one or more apertures are preformed in at least some of the tube sections to facilitate construction of a support means; constructing from within at least one of the tubes and without disturbing the ground surface support means by forcing further tube sections through the ground from within the tube sections, which support means extends to an adjacent tube to form a support structure; constructing further support means from within at least one of the tubes to extend downwardly away from the ground surface and excavating the ground beneath a major pArt of the support structure.
 2. A method of constructing a tunnel comprising forcing a plurality of tube sections substantially horizontally through the ground below the surface of the ground to form two or more horizontally spaced tubes extending lengthwise for a required distance, in which tubes one or more apertures are preformed in at least some of the tube sections to facilitate construction of a support means; constructing from within at least one of the tubes and without disturbing the ground surface support means by augering bores, casing the augered bores, disposing reinforcement within the cased bores and filling them with concrete, which support means extends to an adjacent tube to form a support structure; constructing further support means from within at least one of the tubes to extend downwardly away from the ground surface and excavating the ground beneath a major part of the support structure. 